This relates generally to electronic devices, and more particularly, to electronic devices having plasmonic light collectors.
Plasmonic effects are quantum surface field effects in which an evanescent wave of electron density oscillations is generated on or near a surface of a metal or meta-material in response to incoming, incident light. In structures designed to exhibit plasmonic effects, incoming photons incident on the plasmonic structure generate plasmons associated with high intensity electromagnetic fields within nano-scale distances from the surface of the structure. These high intensity electromagnetic fields couple to the incoming photos and affect the path of travel of the photon near the plasmonic surface. These plasmonic effects may affect light of different frequencies differently. Plasmonic structures may therefore be useful in trapping or otherwise redirecting light of chosen frequencies.
Conventional electronic devices use microlenses formed in a silicon substrate to focus light onto image sensors that convert the light into electrical charge. Image pixels having microlenses formed from structures on a silicon substrate may have a limited efficiency with which light is transferred to the image sensor. Image pixels having microlenses formed from structures on a silicon substrate may require the formation of additional color elements in order to pass or reject light of a chosen color. Microlenses and additional color filter elements may require a volume of space that limits progress in producing smaller electronic devices and may provide limited efficiency in absorbing incident photons of some frequencies.
Plasmonic structures may be designed to reduce pixel size and increase light absorption efficiency in imaging systems in electronic devices.
It would therefore be desirable to be able to provide electronic devices with improved imaging systems.